How to spot a fad diet

From Gwyneth Paltrow-inspired detoxes to baby food-only diets, everybody is desperately searching for the next magical way to lose weight.

But how can you tell the difference between a potentially dangerous fad diet and something that's a little more sustainable?

Easy, says senior nutritionist at Nutrition Australia Aloysa Hourigan: it all comes back to the old adage that if something looks too good to be true, it usually is.

"Fad diets usually promise quick, amazing weight loss, and often have endorsement from a celebrity or two – the idea of a 'quick fix' and the hope of achieving the same 'look' as the celebrity, rather than changing lifestyle behaviours in the long term, is very attractive to people," Hourigan, who's also an accredited practising dietitian, tells Coach.

"But fad diets are not long-term solutions and we need to be ourselves and not be aiming for a societal view of a body ideal."

The fad diet is as popular as ever

In the internet age, with so much evidence and published science available, it's a wonder that fad diets exist at all. But in fact the reality is the exact opposite – the internet is the primary driver for people beginning to think that the only way to lose weight is to do something dramatic.

"Fad diets are in great abundance – there are new fad diets available on the internet or in magazines (especially women’s magazines, but increasingly also in men’s magazines) every day," says Hourigan.

"Results from the Australian Health Survey (taken from ABS data) tell us that in 2011-12, over 2.3 million Australians aged 15 years and over reported that they were on a diet to lose weight or for some other health reason."

Somewhat worryingly, as Hourigan points out, the group most likely to be buying up detox kits and activating their nuts isn't the young, hip millennials – it's their parents.

"Being on a diet was most prevalent among 51-70 year olds where 19 percent of females and 15 percent of males were on some kind of diet."

You could be seriously harming your body

When we hear about celebrities adopting a diet that consists of nothing but bottled air and cocaine, we have a giggle. But when somebody in your family or at work says they're eliminating fat from their diet, we seem to nod sagely.

As Hourigan points out, one of the real indicators of a fad diet isn't necessarily what it asks you to do (like soaking almonds overnight), it's what it asks you not to do (like giving up carbohydrates).

"Many fad diets omit one or more core food groups — common omissions are grains, cereals, and dairy. This means if you follow the fad diet for a period of time, then you could be missing out on key nutrients that are important for health," says Hourigan.

"Many of the 'detox' diets tell you to totally avoid carbohydrate and severely limit kilojoules. This can lead to some negative short-term symptoms including bad breath — smells like acetone or nail polish remover — poor sleep patterns and headaches."

But that's not all. Following a fad diet that involves absurdly low nutrition will definitely help you lose a huge amount of weight, but it'll probably make you look worse too.

"When your energy or kilojoule intake is severely restricted it is likely that your body will break down lean muscle tissue – not just body fat," advises Hourigan.

"So the weight loss you see is partly fat loss and partly muscle loss. Potentially, you could have a poorer body composition — less lean body mass compared to body fat — than what you started with."

The key to any diet is sustainability, not sexiness

We've all heard the stories from family members and colleagues how one particular diet they've done was "pure hell" but delivered "incredible results". All in all, it's really tempting – a little bit of suffering for a whole lot of 'gainz right?

Not really explains Hourigan, because the less sustainable a diet is, the shorter your results will last.

"At the end of the day, you need to ask yourself about whether you will get all the nutrition you need from a particular diet and if the diet plan suggested is something you can continue to do in the long term," says Hourigan.